The equation is $\"\"$ .

Differentiate on each side with respect to $\"\"$ .

$\"\"$

The values of $\"\"$ and $\"\"$ .

$\"\"$

The derivative with respect to is $\"\"$ .

(2)

The area of the square is $\"\"$ .

The side of the square is increasing at rate $\"\"$ .

Let the side of the square is $\"\"$ .

The area of the square is $\"\"$ .

$\"\"$

Differentiate area of the square is $\"\"$ on each side with respect to t.

$\"\"$

Substitute $\"\"$ and $\"\"$ in the above.

$\"\"$

Therefore the rate of change in the area is $\"\"$ .